Preheat your oven to 375°F (190°C) to ensure it’s hot when the ziti is ready for baking.
In a large pot, bring salted water to a vigorous boil. Add the ziti pasta and cook according to the package directions until al dente. Drain the pasta and set it aside in a large mixing bowl.
Heat the olive oil in a large skillet over medium heat. Add the diced onion and minced garlic, sautéing for about 2-3 minutes until they become fragrant and the onion is translucent.
Incorporate the diced bell pepper, zucchini, and yellow squash into the skillet. Sauté the vegetables for an additional 5-7 minutes, stirring occasionally, until they soften. Add the chopped spinach and continue to cook for another 1-2 minutes, just until wilted.
Pour in the marinara sauce followed by the dried basil and oregano. Season the mixture with salt and pepper. Allow it to simmer gently for about 5 minutes, allowing the flavors to meld.
In the large mixing bowl with the cooked ziti, gently fold in the veggie sauce mixture and ricotta cheese. Stir well until everything is evenly combined and the pasta is fully coated.
Transfer half of the ziti and veggie mixture to a greased 9x13 inch baking dish, spreading it out evenly. Sprinkle half of the shredded mozzarella on top. Layer the remaining ziti mixture over this, followed by the rest of the mozzarella, and finish by sprinkling the grated Parmesan cheese on top.
Cover the baking dish tightly with aluminum foil to prevent the cheese from scorching and place it in your preheated oven. Bake for 25 minutes.
After 25 minutes, carefully remove the foil and continue baking for another 10-15 minutes, or until the cheese is perfectly bubbly and has turned a delicious golden brown.
Allow the baked ziti to cool for a few minutes before serving. Garnish with fresh basil leaves for a pop of color and flavor.
Notes
Serve with a crisp salad and garlic bread for a complete meal.